<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>zoomin-zoomout-animation</title>
    <style>
        .zoom-in-out-box {
            margin: 24px;
            width: 50px;
            height: 50px;
            background-color: #2396ef;
            animation: zoom-in-out 1s ease-in-out infinite;
        }
        @keyframes zoom-in-out {
            0% {
                transform: scale(1,1);
            }
            50% {
                transform: scale(1.5,1.5);
            }
            100% {
                transform: scale(1,1);
            }
        }
    </style>
</head>
<body>
    <div class="zoom-in-out-box"></div>
</body>
</html>